Check function type equivalence

pkg/compiler/lib/src/kernel/element_map_impl.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.kernel.element_map;
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../common.dart';
 import '../common/names.dart' show Identifiers;
@@ skipping 401 matching lines @@
     });
     return list;
   }
 
   @override
   InterfaceType getInterfaceType(ir.InterfaceType type) =>
       _typeConverter.convert(type);
 
   @override
   FunctionType getFunctionType(ir.FunctionNode node) {
-    DartType returnType = getDartType(node.returnType);
+    DartType returnType;
+    if (node.parent is ir.Constructor) {
+      // The return type on generative constructors is `void`, but we need
+      // `dynamic` type to match the element model.
+      returnType = const DynamicType();
+    } else {
+      returnType = getDartType(node.returnType);
+    }
     List<DartType> parameterTypes = /*<DartType>*/ [];
     List<DartType> optionalParameterTypes = /*<DartType>*/ [];
     for (ir.VariableDeclaration variable in node.positionalParameters) {
       if (parameterTypes.length == node.requiredParameterCount) {
         optionalParameterTypes.add(getDartType(variable.type));
       } else {
         parameterTypes.add(getDartType(variable.type));
       }
     }
     List<String> namedParameters = <String>[];
@@ skipping 1541 matching lines @@
       if (data.constructorBody != null) {
         f(data.constructorBody);
       }
     });
   }
 
   String getDeferredUri(ir.LibraryDependency node) {
     throw new UnimplementedError('JsKernelToElementMap.getDeferredUri');
   }
 }